What negative psychological state does a sprawling, empty yard cultivate if a GSD is separated there all day?

Answer

Isolation and mental deprivation.

A sprawling, empty yard can quickly become boring, and if it leads to separation, the dog is mentally deprived, cultivating isolation.

What negative psychological state does a sprawling, empty yard cultivate if a GSD is separated there all day?
behaviorDoghousingpetGerman Shepherd